Transition strength

Transition Widths and Strengths. The widths and strengths of spectroscopic transitions determine the information that can be extracted from a spectmm, and are functions of the molecular parameters summarized in Table 2. Detectivity is deterrnined by spectral resolution and transition strength. Resolution, the abiUty to distinguish transitions of nearly equal wavelength, depends on both the widths of the spectral features and characteristics of the instmmentation. Unperturbed transitions have natural, Av widths owing to the intrinsic lifetimes of the states involved. The full width at... 

The properties and computational procedures of the dipole transition strength elements, 2ai(k), are described in several papers [32-33] to which we refer the reader for further details. By partitioning A(k,k ) into Ao(k,k ) and Ai(k,k ) according to ... 

Since the excited levels are determined by searching the poles of the polarization propagator, the poles corresponding to very small dipole transition strengths are difficult to identify. This is particularly the case for the highest energy poles and, consequently, it is not possible to determine by such procedure the top of the conduction band. 

The mixed wave functions were used to calculate B(E2), B(M1) and EO transition strengths. The transition operator for E2 transition is of the form... 

French, R.H., Cannon, R.M., DeNoyer, L.K. and Chiang, Y.-M., (1995), Full spectral calculation of non-retarded Hamaker constants for ceramic systems from interband transition strengths , Solid State Ionics, 75, 13-33. 

Figure 3. Plot of the laser-induced fluorescence intensity per transition strength vs. energy of initial rotational state in 2U(v" = 0) electronic state. The slope of the line gives the OH rotational temperature (13).

The extent to which the IC process is blocked by vibrational deficiency can be ascertained by the quantum yield for fluorescence, <1>F. Such information can be extracted from the measured fluorescence lifetimes, X[, of the vibronic levels of the Sj state, providing the oscillator strength of the S i < S0 transition is known. The radiative lifetime, based on the transition strength, rr, can calculated from the oscillator strength through the expression, xr 1.5//V2. With a measured oscillator strength of / 1.2 x 10 4 and an average transition frequency of... 

Si < S0 transition strength is expected to more efficient for the higher lying vibronic levels of the Si state because of the smaller B2 1A2 perturbation... 

M) /cv = lev cv Ionic strength in molar units. Interband transition strength. 

In practical applications an "interband transition strength" for electrons of mass me,... 

Note Ril/ wavelengths arc optimized values derived from experimental energy levels. Transition Strength F I- I- S I- logl f) Note An accuracy column will be displayed if Z<=28 and transition probability data is displayed. 

We want to emphasize here that the database is quite flexible and allows many other options. For example, in the lines form, if one clicks in the Options field on Set Output Preferences, the Output Preferences form (Fig. 17.8) comes up, and one may select oscillator strengths / rather than transition probabilities, one may select vacuum or air wavelengths, etc. If one clicks on Set Additional Criteria, one may, for example, limit the search to lines of at least a certain minimum transition strength. 

There is an enormous dynamic range in electronic transition strengths (/-/, d-d, CT, n-tv ). 

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